“Want to go running?”

“Sorry, I’m allergic.”

It may sound like the perfect excuse, but can skipping the dreaded Phys Ed Mile or steering clear of running clubs actually be justified? Here’s some good (or bad) news — depending on that level of running love. People can in fact experience an allergic reaction to aerobic exercise, although it’s generally pretty rareExercise-induced anaphylaxis: a serious but preventable disorder. Miller, C.W., Guha, B, Krishnaswamy, G. Department of Internal Medicine, East Tennessee State University, Johnson City, TN. Physician and Sportsmedicine,2008 Dec;36(1):87-94..

No Runny Business — Why It Matters

People usually associate working out with an increased heart rate and a nice rush of endorphins — not hives, fainting, or an itchy rashBeta-endorphin response to exercise. An update. Goldfarb, A.H., Jamurtas, A.Z. Exercise and Sport Science Department, University of North Carolina-Greensboro, NC. Sports Medicine, 1997 Jul;24(1):8-16.. But it could happen: Cholinergic urticaria, a common type of heat rash, can make an irritating appearance when there’s an increase in body temperature or when mast cells in the skin break down right before releasing sweat (read: working out). Studies suggest up to 11 percent of young adults experience this post-exercise hive attack, which is slightly more common in men.

Even worse: There’s a running allergy that can be fatal. Exercise-induced anaphylaxis is a (very) rare allergy that occurs after eating certain foods like wheat, shellfish, and peanuts — and, like the name suggests, it’s triggered by exercise (especially running)Food-dependent exercise-induced anaphylaxis: a case related to chickpea ingestion and review. Wong, C.G., Mace, S.R. School of Medicine, Queen’s University, Kingston, ON. Allergy, Asthma & Clinical Immunology, 2007 Dec 15;3(4):134-7. Epub 2007 Dec 15.. Waiting at the finish line for sufferers: vomiting, difficulty breathing, and hives — not the normal post-run experience. But before hanging up the sneakers and camping out on the couch, the chances of encountering this allergy are extremely low. Researchers estimate it only affects less than half a percent of the Western population (though methods of measuring prevalence haven’t been entirely pinned down yet)Exercise-induced anaphylaxis: an update on diagnosis and treatment. Barg, W., Medrala, W., Wolanczyk-Medrala, A. Department of Physiology, Medical University of Wroclaw, Wroclaw, Poland. Current Allergy and Asthma Reports, 2011 Feb;11(1):45-51..

Sneeze Louise — The Answer/Debate

Running may not be everyone’s favorite fitness activity, but the “I’m allergic” excuse is reserved for those (un)lucky few. Besides the low risk of allergy, only one death from exercise-induced anaphylaxis has been recorded in the past 40 years. And there’s an easy way to prevent an outbreak from this food and exercise allergy: Work out before breakfast, since the reaction occurs only when exercise follows the food.

As for the itchy cholinergic urticaria, its cause is a sudden spike in body temperature, so a slow warm-up may help those temps rise slowly to avoid a sudden breakoutEvaluation of systemic allergy in a jet aviator. Carter, D., Grossman, A., Pokroy, R., et al. Israel Aeromedical Center, Israel Air Force, Tel Hashomer, Israel. Allergy and Asthma Proceedings, 2006 Sep-Oct;27(5):429-30.. Best to skip the Bikram Yoga, though. Or, mix things up and hit the pool to keep the body temperature coolSwimming in ice cold water. Knechtle, B., Christinger, N., Kohler, G., et al. Gesundheitszentrum St. Gallen, Switzerland. Journal of Medical Scientists, 2009 Dec;178(4):507-11. Epub 2009 Sep 11..

Athletes will more likely have run-ins with more common seasonal allergies on the open roadAllergy and asthma in elite summer sport athletes. Helenius, I., Haahtela, T. Department of Allergology, Skin and Allergy Hospital, Helsinki University Central Hospital, Helsinki, Finland. The Journal of Allergy and Clinical Immunology, 2000 Sep;106(3):444-52.. But that’s nothing a trip to the doc and some recommended OTC meds can’t fix. For most of us, our bodies have evolved to lace up those sneaks and hit the roads without a side of BenadrylEvolutionary aspects of human exercise-Born to run purposefully. Mattson, M.P. Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD. Ageing Research Reviews, 2012 Feb 23..

The Takeaway

It is possible to be allergic to running, but the chances are extremely slim.

This article has been read and approved by Greatist Experts Jordan Syatt and Jen Cassetty.

Photo by Jordan Shakeshaft

Does anything funky happen to you when you go for a run? Tell us in the comments below!